Lisp Cabinet for Windows packages several Free implementations with Emacs

Books and tutorials

Experienced programmers

Read Peter Seibel's excellent book Practical Common Lisp, available for free online, or in dead-tree form. This is especially a good book for anyone familiar with programming in other languages and wants to learn Lisp for real-world use.

Novice programmers

If you are new to programming in general, these books may be better choices to begin with: